Good day,

I would like to find out if it’s possible to use solar panels of different wattages together. Currently, I have 9 x 360W panels connected in a single string. I’m planning to expand my system, but I can no longer find 360W panels. Instead, I’m considering purchasing 9 x 450W panels.

My intention is to connect the 9 x 360W panels in one series string and the 9 x 450W panels in another series string, then connect both strings in parallel. Both panel types are rated at 45V.

From an electrical perspective, this setup seems feasible based on my understanding of the rules. However, I’m unsure if this configuration will work effectively in a solar application. Could you please advise?

Regards

14 minutes ago, JJFduPlessis said:

Good day,

I would like to find out if it’s possible to use solar panels of different wattages together. Currently, I have 9 x 360W panels connected in a single string. I’m planning to expand my system, but I can no longer find 360W panels. Instead, I’m considering purchasing 9 x 450W panels.

My intention is to connect the 9 x 360W panels in one series string and the 9 x 450W panels in another series string, then connect both strings in parallel. Both panel types are rated at 45V.

From an electrical perspective, this setup seems feasible based on my understanding of the rules. However, I’m unsure if this configuration will work effectively in a solar application. Could you please advise?

Regards

What inverter are you currently using? What is the direction and tilt of your existing string? What direction will your new string( 9x 450w) face. It is possible to parallel 2 string if direction and tilt is identical. Ensure your scc can handle 7kw hence the question as to the inverter involved. Inverter with 2 x MPPTs would be preferable using diffrent panel wastages and would be most efficient and could then face different directions.

Edited June 25, 2025Jun 25 by TaliaB

8 hours ago, JJFduPlessis said:

My intention is to connect the 9 x 360W panels in one series string and the 9 x 450W panels in another series string, then connect both strings in parallel. Both panel types are rated at 45V

If the strings are pointing in the same direction, you want to match Vmp. Note that the older panels would have degraded by now.

10 hours ago, TaliaB said:

It is possible to parallel 2 string if direction and tilt is identical.

I think from my experience that it would work best if the directions are different. Then the two arrays would not deliver maximum power at the same time and not compete against each other. However make sure your MPPT can handle the combined power. There are moments on partly cloudy days that the panels will deliver up to 20% over specifications.

I have on one MPPT 3 arrays in parallel, each looking in a different direction, one of them vertically installed. Different brands, different age but same number of cells. It works very well, each array giving its maximum at a different time of the day.

Thank you for your reply. Based on my experience, the 5kW Kodek inverter with a 4kW MPPT will only accept up to 4kW of solar input, even if you install more than 4kW worth of panels. That’s the maximum it can handle.

Once your batteries are fully charged, the system will only draw the amount of power it needs from the panels. All the panels will be installed facing the same direction and at the same angle.

The reason I want to add that number of panels is to help the system reach its maximum power output earlier in the day, maintain it later into the afternoon, and improve performance on cloudy days